Method of forming a grain door



Dec. 27, 1960 B. H.' FORD 2,966,438

METHOD OF FORMING A GRAIN DOOR Filed July 1, 1957 /N VEN TOR.'

ATTORNEYS United States Patent METHOD OF FORMING A GRAIN DOOR Barton H.Ford, Omaha, Nebr., assigner, by mesne assignments, of one-half toInternational Paper Company, New York, N.Y., a corporation of New York,and one-half to The Stanley Works, New Britain, Conn., a corporation ofConnecticut Filed Jury 1, 1957, ser. N0. 669,033 -4l Claims. (c1.154-118) This invention relates to a method for forming a grain door,and, more particularly, a closure for a railway car doorway or carbarricade.

The present application is a continuation-in-part of my copendingapplication, Serial No. 568,482, tiled February 29, 1956.

An object of .the present invention is to provide a method for forming agrain door in an expeditious manner so that it may be set up andemployed with a minimum of labor and elort. A further object is toprovide a method for fabricating a grain door which lends itself tomachine operations so that the door can be com pletely fabricated at lowexpense while at the same time providing a door which may be installedwith important new advantages and which has the further advantage ofexposing automatically the reinforcing steel straps for nailing the sameto the door frame. A still further ob ject is to provide a grain doorwhich may be fabricated in one or more panels and folded into a compactform for shipment, while at the same time permitting ready applicationto a door frame. Other specific objects and advantages will appear asthe specification proceeds.

The invention is shown, in illustrative embodiments, by the accompanyingdrawing, in which- Figure 1 is a perspective view of a railway carequipped with a closure embodying my invention; Fig. 2, a broken rearview of the corrugated board employed; Fig. 3, a vertical sectionalview, the section being taken as indicated at line 3-3 of Fig. 1; Fig.4, an enlarged broken sectional view, the section being taken asindicated at line 4--4 of Fig. 2; Fig. 5, an enlarged sectional detailview, the section being taken as indicated at line 5-5 of Fig. 2; andFig. 6, a sectional view showing the method of assembly of the parts inaccordance with a method embodying my invention.

In the illustration given, A designates a portion of a railway car, andB designates my grain door applied thereto. The car portion A is shownprovided with a floor 1li and a side wall `11 provided with an opening12 surrounded by a door frame 13.

The 4grain door or closure B comprises a corrugated board 14 having aninner corrugated core 15, the core 15 lying between an inner liner 16and an outer liner 17. The inner liner 16 is bonded to the core 15 bythe glue layer 18, and the outer liner 17 is bonded to the core 15 bythe glue layer 19. Metal straps 20 extend in spaced relation between theouter liner 17 and the outer bends of the core 15. The straps 2li arepreferably provided with spaced openings 21 through which nails may bedriven to secure the ends of the straps to the frame 13.

The corrugations or flutes 15 preferably extend vertically in the board14, and the straps 20 abut the outer edges of the spaced bends of thecore 15, as shown best in Figs. 4 and 6.

The board 14 is provided adjacent its side edges with score lines 22 soas to permit the corrugated board to be turned inwardly to provide sideaps 23. Since the outer liner 17 is formed of paper or other frangiblematerial, the liner tears away from the metal straps 20 to leave themlying iiat against the frame 13 so that they may be readily nailed inposition while the ilap is drawn rearwardly, as illustrated in Fig. 1.After the nailing operation, the flap 23 may be moved backwardly inplace and a batten 24 or other suitable means employed for securing thetiap in a position over the nailed strap ends 2t). The corrugated boardis preferably also scored along line 25 near its bottom to provide abottom flap 26. A pry-board 27 may be nailed above the tlap 26 and aheadboard 28 may be secured over the top portion of the door.

In the foregoing installation operation, it will be observed that animportant feature is the ready separation of the ap 23 from the metalstraps 20. While the door is being shipped to its destination or isbeing handled preparatory to installation, it is desired that the sharpmetal ends of straps 20 be securely sheathed within the door by thepaper liners, but when the door is to be installed, it is desired thatthe straps be readily exposed for nailing when the liaps 23 are bentinwardly. This is accomplished by forming the outer liner 17 of paper orother frangible material, and I prefer also to provide the outer linerwith spaced slits 29 about each of the straps so that the liner tearsalong true and cleancut lines. It is preferred that the slits 29terminate at a spaced distance from the edge of the liner sheet, asindicated at Si?, so that a tongue segment of the paper confines theseslitted portions of the liner about the metal straps. Instead ofslitting, perforations or other means for providing weakened lines aboutthe straps, may be employed to provide a ready tearing of the liner.

I have discovered that by locating the metal strap 2th directly againstone side of the core 15, there is a minimum of contact between the strap20 and the core, and this aids in the ready separation of the strap fromthe core even though the core be initially provided with glue forbringing about a ready attachment of the core to the liner strips 16 and17. If desired, an oil film 31 may be provided over the side of themetal strap 20 adjacent the core 15 to bring about ready separation.

The new door structure may be formed expeditiously and with a minimum ofcost with the apparatus illustrated in Fig. 2. Rollers 32 and 33,mounted on driven shafts 34 and 35, respectively, compress between themthe core 15, the inner liner 16, and the outer liner 17 to bring theliners into contact with the core 15, the core 15, or the inner edges ofthe liners 16 and 17, being previously provided with adhesive. Spacedstraps 2t) are fed simultaneously between the core 15 and the outerliner 17 so as to form in one operation a complete door strip which isadvanced continuously. Later, the strip is cut into sections for theindividual doors. Slits are formed in the doors, as illustrated in Fig.2. If desired, the strips 211 may be on the outside of the liner 17 anda second gurnmed liner (not shown) may be employed for conning the strap2d against the outer side of liner 17, all as shown in greater detail inmy copending application, Serial No. 568,482. I prefer, however, tosecure the straps Ztl in position directly against the core 15 for theadvantage that the straps 20 may later be readily separated from the aps23 when the same are folded inwardly.

While, in the foregoing specification, I have set forth a structure andmethod in considerable detail for the purpose of illustrating the.invention, it will be understood that such details of structure andprocedure may be varied widely by those skilled in the art withoutdeparting from the spirit of my invention.

I claim:

l. In a process for continuously forming a grain door, the steps ofpassing between forming rollers a corrugated medium enclosed betweenfrangible liner sheets while simultaneously passing flat metal straps inspaced relation between one of said liner sheets and said corrugatedmediurn and transverse to the utes of said medium.

2. In a processV for continuously forming closure doors, the steps ofpassing between forming rollers a continuous strip of corrugated mediumand frangible paper liners on both sides of said medium and withadhesive between said medium and liners while simultaneously feeding atmetal straps in spaced relation between one of said liners and saidcorrugated medium and the spaced relation against said corrugatedrnediurn andl transverse to the flutes thereof to bond `said one linerto said straps and said corrugated medium, and severing the resultingboard into door panels.

3. In a processk for continuously forming grain doors, the stepsofpassing between forming rollers a continuous strip of corrugated papermedium with frangible paper liners on both sides of'said medium and withadhesive for bonding said liners to said medium while simultaneouslyfeeding flat steel straps in spaced relation along the face of one sideof said corrugated medium transverse to the utes thereof and bonding oneof said liners to said straps and said corrubated medium while bondingthe other liner directly to said corrugated medium, and severing theboard into door panels, said board being scored at transverse verticallines adjacent the edges of the board to provide aps which may be drawnrearwardly to separate the aps from said steel straps.

4. In a process for continuously forming a corrugated panel adapted tobe installed in a grain car, the steps of passing between formingrollers a corrugated medium enclosed between frangible liner sheetswhile simultaneously passing at metal straps in spaced, parallelrelation between one of said liner sheets and said medium and transverseto the ilutes of said medium, and severing the resulting panel alongspaced-apart lines parallel to the flutes of said medium.

References Cited in the leof this patent UNITED STATES PATENTS1,410,622y Swift` Mar. 28, 1922 1,425,914; Swift Aug. 15, 1922 1,600,396Campbell et a1. Sept. 21, 1926 2,794,761 Williamson June 4, 1957 FOREIGNPATENTS 214,797 Great Britain May 1, 1924 UNITED STATES PATENT TTTCECERTIFICATION 0F CORRECTIN Patent No. 2,966,438 December 27, 1960 BartonH, Ford It is hereby certified that error appears in the above numberedpatern?l requiring correction and 'that the said Letters Patent shouldread as corrected below.

Column 3, l

ine l2, for "the" read for "corrubated" m in w-; line 25, readcorrugated Signed and sealed this 6th day of June l96l (SEAL) Attest: y

Commissioner of Patents

1. IN A PROCESS FOR CONTINUOUSLY FORMING A GRAIN DOOR, THE STEPS OFPASSING BETWEEN FORMING ROLLERS A CORRUGATED MEDIUM ENCLOSED BETWEENFRANGIBLE LINER SHEETS WHILE SIMULTANEOUSLY PASSING FLAT METAL STRAPS INSPACED RELATION BETWEEN ONE OF SAID LINER SHEETS AND SAID CORRUGATEDMEDIUM AND TRANSVERSE TO THE FLUTES OF SAID MEDIUM.